Muscular system

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The muscular system consists of muscles that allow movement of the body, maintain posture, and circulate blood throughout the body. The main functions of the muscular system are:

• Movement: Muscles contract and relax to cause movement of the body. They allow us to walk, grasp objects, smile, breathe, etc. Different muscles work together in an integrated fashion to coordinate complex movements.
• Maintaining posture: Muscles keep the body in an erect posture by making minor adjustments to the position of the back, neck and limbs. Posture muscles often work at a low level of activity but are constantly active.
• Circulatory support: The muscular system works with the circulatory system by pumping blood through veins, especially in the legs. Leg muscles compress veins and push blood upwards against gravity.
• Stabilization: Some muscles work to stabilize and anchor other tissues and organs. For example, muscles stabilize bones and joints, assist in breathing by keeping rib cage open, stabilize internal organs, etc.
• Heat generation: Muscle activity generates heat as a byproduct and helps maintain body temperature. Shivering in response to cold also generates heat.

The major types of muscles in the muscular system are:

• Skeletal muscles - Attach to bones and cross joints, allowing limb movement. Voluntary control.
• Smooth muscles - Line internal organs like stomach, intestines. Involuntary control.
• Cardiac muscle - Forms the heart muscle. Involuntary control. Heartbeat is stimulated by pacemaker cells.

The muscular system consists of over 600 muscles that make up about 40% of the body mass. Muscles receive signals from the nervous system to coordinate their activation and produce smooth and purposeful movement.

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Transcript:-
The muscular system provides forces that facilitate the body to move and maintain posture. The muscular tissues are highly specialized for contraction, and hence these are also known as contractual tissues. The muscle cells are slender and highly elongated and are known as muscle fibers. The cytoplasm of a muscle fiber is called sarcos.

The Sarco Plasm is provided with fine longitudinal fibers called myofibrils. A muscle fiber may be provided with a nucleus and usually bounded by a specialized membrane called sarcolemma. The human body has about 700 muscles, and these belong to three classes based on histology, anatomy and physiology.

As follows, visceral or smooth, involuntary skeletal or striated, voluntary and cardiac or imperfectly, cross striated, involuntary, smooth muscles or visceral muscles are found in the walls of the hollow internal organ. The smooth muscle fibers are slender, elongated, with pointed ins and without cross striations.

Each fiber has a single nucleus, but sarcolemma is absent. These fibers have nerve supply from the sympathetic and the parasympathetic nervous system. They undergo slow rhythmic contract. And relaxations that are responsible for creating peristaltic movements. These muscles are involuntary since the contraction is not under the control of will.

Examples include the wind pipe, gastrointestinal tract, bladder, uterus, and blood vessels.

The skeletal muscles are found attached to the bones. Several fibers unite to form small bundles, which in turn are bound by the connective tissue to form the skeletal muscles. The skeletal muscle fibers are long cylindrical with non tapering ins. The fibers are multi-nucleated with the nuclei scattered all along the.

These fibers exhibit a series of alternating light and dark transverse or cross bands or striations. Each muscle fiber is surrounded by a tough membranes sheath called sarcolemma. They have both the sensory and motor nerve supply from the central nervous system. The skeletal muscles undergo quick or sudden contractions that are voluntary and hence under the control of will.

Some skeletal muscles also exhibit involuntary nature. For example, the thoracic diap. The cardiac muscles are present only on the wall of the heart. They are intermediate in structure between the untreated and striated muscles. Each muscle fiber is uni nucleated. These fibers are branched and are interconnected by a cross connection forming a contractual network.

Transverse striations are present but are relatively weak. An ill-defined sarcolemma is present. The muscle fibers have dark, thick interated discs called end plates at regular intervals. The fibers have nerve supply from the brain as well as from the autonomous nervous system. The cardiac muscles are involuntary muscles with rhythmic contractions, which results in the rhythmic contract.

Of the heart. The term muscular system is mainly used for the skeletal muscles that are voluntary in nature. These muscles are connected to the bones, cartilages, ligaments, and skin directly or through tendons or epi neurosis. The ends of the skeletal muscles are attached by tendons to two different bones, only one of which moves when the muscles.

Muscles that bend joints and pull limbs towards the body are called flexos. Muscles that straighten joints are called extensor. The muscles of the human body may be subdivided into the axial and the apendicular muscles. The axial muscles refer to the muscles attached to the head, neck, vertebra, column, thorax, abdomen, pelvic floor, and perineum.

They positioned the head and spinal column for non-verbal communication, chewing and swallowing. They also moved the ribcage to aid in breath. The axial muscles account for 60% of the skeletal muscles. The muscles of the face, head and neck include muscles of the facial expression, mastication, chewing tongue pharynx, and the extrinsic eye muscles involved in the movements of the eye.

These muscles arise on either the skull or the hyoid Bone. Muscles involved with hearing are also based on the skull. The largest group of facial muscles is associated with the mouth and includes the vaccinator, depressor, labi, inferiors, lader, Labi, superiors, Orbis Oris. Rosas Depressor, anguli Oris, zygomaticus major and Zygomaticus minor.

The vaccinator is the muscle of the cheeks that cooperates with the atory muscles to move the food across the teeth and in infants. It helps in sucking the vaccinator also helps in actions such as blowing or whist. The depressor Labi inferiors originates from the mandible and is involved in moving skin tissues around the lower jaw while the lader Labi Superioris is located between the upper lip and the lower orbit of the eye.

It's main function being raising the facial tissue upwards from the upper lip. The men is found attached to the skin of chin and is involved in its upward movement. The Orbicularis ORs encircles the mouth and lips and plays a role in closing of the mouth. The SIUs, commonly known as the laughing muscle is inserted at the corners of the mouth and is involved in smiling expression depressor anguli.

Orus is the muscle located in the lower jaw area and draws the mouth laterally and inferiorly as seen during opening of the mouth. The Zygomaticus major extends from the ears across the face and is involved in upward and outward movement of skin tissue, while the Zygomaticus minor extends across the face, similar to the Zygomaticus major, but is involved in elevating the upper lip.

Small groups of muscles control movements of the eyebrows, eyelids, scalp, nose, and the external ears. The eran or occipital frontals. The scalp muscle has two parts, the frontal belly and the occipital belly covering the forehead and back of the head, and involved in raising the eyebrows and forming wrinkles in the skin of the.

The platysma or the neck muscle covers the ventral surface of the neck and extends from the base of the neck to the periosteum of the mandible. Six extrinsic muscles or oculomotor muscles that control the position of the eye, originate on the orbit and insert onto the sclera. The six extrinsic eye muscles are the medial lateral, inferior and superior rectus muscles, and inferior and superior oblique muscles.

The muscles of mastication or chewing move the mandible at the temporal mandibular joint. The large rectangular massacre, the strongest jaw muscle extends from the cheek to the outside of the jaw, and the triangular temporalis muscle is located on the side of the head. Both these muscles assist in closing of the jaw.

The TeraGo muscles located deep inside the jaw. Elevate, depress or protract the mandible or slide it from side to side called the lateral excursion. The muscles of the tongue help it to move in delicate and complex patterns for proper speech. They are also involved in manipulating the food for swallow.

The muscles of the tongue include the pgl muscle that originates on the soft pate, the styl glasses muscle with origin from the stylo processes of the temporal bone, the geno glasses muscle arising from the mandible, and the high OGLs muscle originating from the hyoid. The muscles of the pharynx initiate swallowing and include the pharyngeal, constrictors, superior, middle, and inferior that constrict the pharynx and move the food inferiorly into the esophagus.

The muscles of the larynx are necessary for the movement of vocal chords to initiate breathing and in production of voice. The laryngeal elevators take part in elevating the laryn. The palatal muscles elevate or tense the soft palate and prevent the food from entering into the nasopharynx as well as cyst in opening of the auditory tube.

The muscles of the neck help in swallowing and moving the head. The anterior muscles of the neck in particular control the position of the larynx, depress the mandible, tense the floor of the mouth, and give a firm foundation for the pharyngeal muscles and muscles of the. . The digastric muscle myelo, hyoid muscle styl, hyoid, muscle omo, hyoid muscle, sterno, hyoid, and sterno.

Thyroid muscles scaling muscle, and sternocleido mastoid muscle belong to this category. The digastric muscle has two bellies, the anterior belly extending from the mandible to the hyoid bone and the posterior belly extending from the hyoid bone to the mastoid portion of the temporal bone. These muscles depressed the mandible and open the mouth or elevate the hyoid bone.

The mylohyoid muscle forms the muscular floor of the oral cav. The Tylo hyoid muscle originates from the S styloid process and inserts on the hyoid bone. Its main function is to pull the hyoid bone backwards and elevate the tongue. The omo hyoid muscle connects the scapula to the hyoid bone and depresses and stabilizes the hyoid.

The Sterno hyoid muscle attaches the hyoid bone to the sternum and serves to depress the hyoid bone in head and neck movement and speech. Hi, my name is Adam. The Sterno thyroid muscle attaches the sternum to the cartilage near the thyroid gland, and pulls the larynx downwards when it contract. The scaling muscles are present on either side of the neck in three separate parts, beginning at the first and second ribs and passing into the sides of the neck.

These muscles aid in breathing and movement of neck. The Sterno CDO mastoid muscles, also known as the Sterno mastoid muscle, or S c m, are a pair of long, thick muscles that extend from the medial clavicle and sternum to the mastoid process of the skull. They play an important role in the movement of the head, apart from functioning as accessory muscles during inspiration.

The muscles that encase the torso hold the body, erect, allow it to flex, assist in breathing and restrain the intestines. The back muscles that control the torso's forward and backward movement originate primarily along the upper crest of the hip, the sacra, and the lumbar vertebrae at various levels.

Several large muscles that restrain the abdominal contents, bend the spine and assist in breathing, pass vertically, horizontally, and diagonally across the abdominal cavity. There are five pairs of muscles that form a part of the abdomen, rectus, abdominus, internal oblique, external o. Transversus Abdominus and Quadras lumbo.

The oblique and rectus muscles lie between the ribs and pelvic region. The oblique muscles help in twisting the trunk. The Rectus Abdominus, also known as Six Pack, is a pair of parallel running muscles present on each side of the anterior wall of the abdomen. It is vital for flexing the lumbar spine, breathing and creating intraabdominal pressure during.

The Transversus Abdominus is the deepest muscle of the abdominal wall that arises from the cartilages of lower six ribs and extends till the pelvic region. It helps in stabilizing the pelvis and lower back during movement of the body and assists in forced expiration. The quadras Lium arises from the iliac crest and attaches to the 12th

Helping in lateral flexion of the spine rotation and stabilization of the last rib during inhalation and forced exhalation. The main muscles of the thorax that help in breathing are external and internal intercostal muscles, and the diaphragm. There are 11 pairs of intercostal muscles. The external intercostal muscles extend downwards and forwards in between the ribs and are involved in inhalation while the internal intercostal muscles extend down.

and backwards between the ribs and are involved in exhalation. The diaphragm is a dome shaped sheet of skeletal muscle that extends across the bottom of the ribcage and separates the abdominal, pelvic and thoracic cavities. The diaphragm aids in breath. The Apendicular musculature refers to the muscles of the arms and legs that move the upper and lower limbs, as well as stabilize and control the movements of the pectoral and pelvic girdles.

These muscles can be divided into two major groups, one, the muscles of the upper extremities that include the shoulder and upper limb. And two, the muscles of the lower extremities, which include the pelvic girdle and lower limbs. The muscles of the upper extremities stabilize and assist in the movement of the shoulders and upper limbs.

These muscles are organized into one muscles of the pectoral girdle, two muscles that move the glenohumeral joint or. Three muscles of the forearm and the hand, and four muscles of the hand and fingers. The muscles of the pectoral girdle can be divided into the anterior and posterior muscles. The large triangular, superficial trapezius muscles that cover the posterior neck and the upper back originate on the axial skeleton and insert on the clavicles and the scapula.

It elevates and retracts the scapula and assists in movement of the neck. , the ramidus and lader scapula muscles on the dorsal side of the thoracic vertebra column retract and elevate the scapula respectively. The fan shaped sarus anterior muscle on the chest originates along the anterior surfaces of the upper eight ribs and inserts along the medial border of the scapula.

It plays a role in rotating and retracting the scap. The subclavius muscle and pectoralis minor muscle arise along the ventral surface of the ribs on either side of the chest and insert on the inferior border of the clavicle and coracoid process of the scapula respectively. These muscles ProTrac the scap.

Muscles that move the glenohumeral joint or the arm include the pectoralis major and cortico brachialis on the anterior side and the deltoid rotator cuff muscles supraspinatus subscapularis in infraspinatus and terrace, minor terrace, major infraspinatus muscle, and latisimus doorside on the posterior.

The deltoid muscle that covers the shoulder joint and upper humus is the major abductor, but the supraspinatus muscle assists to begin this abduction. The subscapularis and terrace major muscles medially rotate the humus while the infraspinatus and terrace minor muscles rotate the humorous laterally.

All these muscles originate from the scap. The Latisimus dorsi muscle originates from the lower thoracic vertebrae and inserts onto the inter tubercular grove of the humus, and is involved in extending the shoulder. The pectoralis major muscle on the anterior portion of the chest inserts onto the greater cubicle of the humus and flexes the shoulder.

The pectoralis major and the latisimus doorside together, abduct and medially rotate the arm. The small cortico brachialis muscle attached to the scapula produces both flexion and abduction at the shoulder. The biceps brachy e muscle, and the long head of the triceps brachy e muscle originate on the scap.

The triceps Bray e muscle that extends the elbow inserts on theon, whereas the biceps Bray e muscle that flexes the elbow and supes the forearm inserts onto the radius. The superficial muscles such as flexor carpi, ois flexor carpi radialis, and palm Marris longest worked together to flex the. Several superficial and deep muscles of the forearm produce flexion and extension at the finger joints.

These muscles extend till the wrist and only the tendons cross the articulation. The muscles are large and aid maximum mobility at both the wrist and the hand. The tendons that cross both the sides of the wrist pass through the tendon sheaths, which are elongated bursa that reduce friction. The muscles of the forearm called extrinsic muscles provide strength and crude control of the hand and fingers, whereas the small intrinsic muscles that originate on the carpal and metacarpal bones provide fine control of the hand.

Only the tendons extend across the distal joints of the fingers and no muscles originate on the phalanges. The pelvis and the lower limb consist of the biggest muscles of the body as they aid in weightbearing. The pelvic girdle is tightly bound to the axial skeleton, and only little movement is permitted.

These muscles are organized into functional groups such as muscles of the hip, muscles of the thigh, muscles that move the. And muscles that move the foot and toes, the muscles of the hip help inflection of the hip joint and include the sous and the Elias. The sous muscle originates from the transverse processes of the lumbar vertebrae and insert into the.

The Elias originates from the iliac crest and inserts into the lesser tro cantor of the femur. The combined action of the SOS and the iliacus flexes the hip joint. There are various muscles present on the anterior and posterior side that form a part of the thigh. There are three gluteal muscles that cover the lateral surface of iea.

They are gluteus maximus, glutes medias, and gluteus mini. Glut Maximus is the largest and most superficial of all three muscles. It inserts along with the tense sore fasci, E latei muscle, which originates on the iliac crest between the cubicle of iliac crest and anterior superior iliac spine. They both together insert into the ilio tibial tract that provides a lateral brace for the.

The gluteus medias and gluteus minimus muscles arise anterior to the origin of gluteus maximus, and together insert onto the greater tro cantor of femur. The gluteal muscles cause extension, abduction, and medial rotation at the hip joint, the six lateral rotator muscles, Perfors jamus superior. Obturator Internis Jamis, inferior obturator externus quad fems arise at or inferior to the horizontal axis of the acetabulum, among which the perfors muscles and the obturator muscles are dominant.

These muscles help an external rotation of the femur at the hip. The abductors arise from the pubic bone and insert into the medial and posterior aspect of the. The adductors include the adductor magnus, abductor, brevis, abductor, longus, pectins, and gracillis muscles. The abductor magnus muscle either adducts and flexes or adducts and extends the hip joint as well as produces medial or lateral rotation at the hip.

The other muscles abduct and rotate the thigh medially. The same as the upper limb. The lower limb also exhibits a pattern in muscle distribution. The extensor muscles are found along the anterior and lateral surfaces of the leg, and the flexor are located along the posterior and medial surfaces. The three hamstring muscles, biceps, fems, semiosis, and semi tendonosis arise along the edges of the pelvis and insert on the tibia.

These, along with the sartorious muscle contract to flex the knee, the four knee extens. Rectus fems and three vasti laterals, medias and intermedius together form the quadriceps femorals. All these muscles are attached to the patella and relay the force of their contraction to the tibial tuberosity through patellar tendon.

The rectus fems is the only muscle in this group that flexes the hip joint. Most of the extrinsic muscles that move the foot and toes are involved in plantar, flexing and assist in walking and running the gastro rockem muscle of the calf and the underlying soleus muscles share a common tendon called calca tendon, also known as Achilles tend.

The Peronial muscles, also known as fibs muscles are a group of three muscles that originate from the fibula and insert into the tarsals and metatarsals. These muscles are involved in aversion and plantar flexion of the foot. Important digital muscles arise on the tibia, the fibula, or both, and include the tibialis anterior.

Extensor Digitorum longus and the extensor halus longus muscles, large sheaths of tendons surround the tendons of these muscles where they cross the ankle joint. The intrinsic muscles of the foot originate on the tarsal and metatarsal bones. These muscles contract to move the toes and also maintain longitudinal arch of the foot.

The highly specialized muscular tissue facilitates the posture and movement of the body, the comprehension of different kinds of muscle. Muscles on different parts of the body and their functions as graphically elucidated in these videos go a long way in understanding this basic system of the human body.